Sunday's DFL endorsing convention for Hennepin County's soon-to-be-vacant Second District board seat could either anoint Mark Stenglein's successor -- or really throw the race wide open.

The convention, which starts at noon at Edison High School in northeast Minneapolis, will pit three DFLers against each other for the party nod. Three others also are running for the seat but won't be seeking backing at the party convention.

The Second District is arguably the county's most diverse, stretching from Plymouth through north and northeast Minneapolis to St. Anthony.

As with most Minneapolis districts, it's considered a DFL stronghold, and party backing carries weight and resources. With no candidates yet declaring themselves from Republican, Green or Independence party ranks, it's possible that the next commissioner will be selected at the convention Sunday.

Then again, it's also possible that the votes of the 150 delegates expected to attend will be so divided that the convention will be deadlocked and no endorsement will be given.

Which, in turn, could point to a wild and woolly primary battle in August.

The district's politics have been unpredictable before. In 1996 Stenglein, then a 40-year-old businessman who had never run for office, challenged DFL incumbent Sandra Hilary. He didn't seek DFL endorsement, running instead as an independent.

Hilary got party backing after coming in behind Stenglein in the primary election, but he still defeated her in November by a narrow margin.

Stenglein, of northeast Minneapolis, continued to run as an independent until 2010, when he ran as a DFLer and won with 72 percent of the vote. He's resigning from the board May 31 to become president and CEO of the Minneapolis Downtown Council, an influential business group.

Because the seat will be vacant, the winner will take office immediately after the November election and serve two years before facing election for a regular four-year term in 2014.

Stenglein said Friday that he's not making an endorsement.

Here's a look at the DFLers squaring off Sunday:

Jill Davis, of northeast Minneapolis. Davis, 50, is a psychologist who supervises family programs in Anoka County and has been a Minneapolis school board member since 2009. She is endorsed by Minnesota NOW and Women Winning. Campaign Chair Alexis Pennie said that Davis won't run in the primary if someone else wins the endorsement.

Linda Higgins, of north Minneapolis. Higgins, 61, announced in 2011 that she would step down as state senator this year after five terms. She readjusted her sights after Stenglein said in February that he was leaving the board. She is endorsed by AFSCME, the Teamsters and Letter Carriers unions, Minnesota Nurses Association and U.S. Rep. Keith Ellison. Higgins said she will abide by the endorsement if it goes to someone else.

Don Samuels, of north Minneapolis. Samuels, 63, has been on the Minneapolis City Council for nine years. Before that, he designed toys and earned a divinity degree from Luther Seminary. Samuels, who is endorsed by Mayor R.T. Rybak, said he was undecided about whether he will run in the primary should someone else win the endorsement.

Others moving to primary

Three others plan to run in the August primary election and are bypassing the party endorsement process.

They are Tonia Johnson, 45, of north Minneapolis, a small-business owner, Minneapolis Charter commissioner and former policy aide to Stenglein; Paula Pentel, 55, of Golden Valley, an instructor and adviser with the University of Minnesota's Urban Studies program who has served on the Golden Valley City Council for eight years; and Blong Yang, 36, of north Minneapolis, an attorney and investigator with the Minneapolis Civil Rights Department. This will be the first campaigns for Johnson and Yang, who are running as DFLers. Pentel is running as an independent.

Kevin Duchschere • 612-673-4455